Log turner



1965 J. s. MELLOTT ETAL. 3,269,432

LOG TURNER 5 Sheets-Sheet 1 Filed Oct. 7, 1963 INVENTORS JOHN s MELLOTT BY HAYES R. MELLOTT 6 W, 424%) ATTORNEYS Aug. 30, 1966 J. 5. MELLOTT ETAL 3,259,432

LOG TURNER Filed 001;. 7, 1965 5 Sheets-Sheet 2 INVENTORS JOHN S. MELLOTT BY HAYES R. MELLOTT A TTORNEYS g- 30, 1966 J. 5. MELLOTT ETAL 3,269,432

LOG TURNER Filed Oct. '7, 1965 5 Sheets-Sheet 5 1 06 gig INVENTORS JOHN S MELLOTT HAYES R. MELLOTT ATTORNEYS United States Patent 3,269,432 LOG TURNER John S. Mellott and Hayes R. Mellott, both of Rte. 1, Box 97, Mercersburg, Pa. Filed Oct. 7, 1963, Ser. No. 314,389 8 Claims. (Cl. 14399) This invention relates to saw mills, and more particularly to an improved log turner for turning a log on the carriage of a saw mill.

In the operation of a saw mill it is necessary to turn each log on the carriage of the mill a number of times as the sawing operation progresses. A number of devices have been developed for turning the logs by engaging and lifting the outboard side of the log and thereby rolling or spinning the log against the retaining vertical face of the adjustable knees on the log carriage. Such turning devices commonly comprise a driven endless chain mounted on an arm which is pivotally mounted beside the carriage track of the mill. When it is desired to turn the log, the arm is pivoted to a position so that a generally vertical length of the chain engages the outboard side of the log. The chain is then driven in a direction so that the length engaging the log moves in an upward direction, and teeth, or projections, carried by the chain tend to lift the outboard side of the log, thereby rolling or spinning the log against the vertical face of the adjustable knee.

While these log turners are effective in turning the log on the carriage, they have not been entirely satisfactory in that the force exerted on the log by the turner tends to force the turner into a more firm engagement with the log. This results in an increased lateral force exerted on the adjustable knees and, consequently, an increased force required to turn the log. Also, this increased force tends to cause the teeth carried by the chain to damage the face of the log. In the case of large and heavy logs, this lateral force can be so great as to damage the adjustable knees and, in some instances, cause the carriage to be lifted from the track.

Accordingly, it is an object of this invention to provide an improved endless log turner for turning a log on the carriage of a saw mill.

Another object of this invention is to provide a pivotally mounted log turner having an endless chain for turning a log on the carriage of a saw mill, and which will not exert excessive forces on the knees of the carriage.

Another object of this invention is to provide a pivotally mounted endless chain log turner which will not cause excessive damage to the surface of the log being turned.

Another object of this invention is to provide a pivotally mounted endless chain log turner having means to limit the lateral force exerted by the turner on the log.

Another object of this invention is to provide a pivotally mounted endless chain log turner having means to maintain a constant, predetermined lateral force exerted by the turner on the log regardless of the force required to turn the log.

In the attainment of the foregoing and other objects, an important feature of our invention resides in pivotally mounting the log turner at a point beneath the carriage of the saw mill so that the line of action of the reaction force exerted by the log on the turner will pass outboard of the pivot point and thereby tend to rotate the turner away from engagement with the log. A fluid motor is employed to rotate the turner about the pivotal mounting to engage the log on the carriage and maintain the desired lateral force on the turner to permit the moving chain to turn the log.

Other objects and advantages of the present invention Patented August 30, 1966 will become apparent from the following detailed description taken in conjunction with the attached drawings.

In the drawings:

FIG. 1 is an end elevation view of a .saw mill employing a log turner according to the present invention with the turner shown in the raised position to engage a log on the saw mill carriage.

FIG. 2 is an elevation view similar to FIG. 1 but showing the turner in the retracted position.

FIG. 3 is a sectional view taken on line 33 of FIG. 1.

FIG. 4 is a fragmentary view taken on line 44 of FIG. 1.

FIG. 5 is a partially schematic sectional view of the fluid actuating means for moving the turner between the log turning position and the retracted position.

Referring to the drawings, a saw mill is shown having a carriage 12 moveably mounted on tracks 14 for supporting and conveying a log 16 into engagement with a fixed position rotary saw not shown. Log 16 is rolled down a ramp 20, and positioned on the receiving edge 18 of carriage 12 by knees 22 which are adjustable laterally of the carriage. The log is retained in position by dogs (not shown) mounted on the adjustable knees in position to engage an upper surface of the log.

As individual boards are sawed from the log, the adjustable knees are moved laterally to slide the log across the carriage in position to remove another board. When it is desired to turn the log, log turner 24 is raised to engage the outboard side of the log as shown in FIG. 1.

Log turner 24 com rises a beam 26 pivotally mounted at 28 to frame 30 at a point beneath carriage 12. Beam 26 is a generally rectangular hollow member preferably formed from a pair of structural channels 31, 32 mounted as by welding to a base member 33. Base member 33 includes a hollow tubular member 34 pivotally mounted in journals 36 of side members 38 of frame 30. A pair of sprockets 4t], 42 are mounted in beam 26 for rotation in the plane of rotation of beam 26, and support an end less chain 44 having a plurality of teeth 46 projecting upwardly from selective teeth in the chain. A tapering wedge 43 is attached to surface 50 of beam 26 beneath chain 44 to project the bottom portion of chain 44 upwardly from face 50 of beam 26. Guides 52 are attached to face 50 of beam 26 to guide 44 in its movement along beam 26.

A fluid motor is pivotally mounted at 62, and is pivotally connected at 64 to line 66 which, in turn, is pivotally connected at 68 to downwardly extending projections 70 of base member 32. Fluid under pressure acting on a piston in motor 60 will cause rod 72 to be retracted, thereby rotating projection 70 about pivotal mounting 28 to raise the log turner from the retracted position shown in FIG. 2 to the raised position shown in FIG. 4. When fluid pressure is released from motor 60, permitting rod 72 to be extended, the log turner will move by force of gravity to the retracted position shown in FIG. 2. In the retracted position a stop member 74 engages cross member 76 of frame 30 to support the weight of the turner.

In order to maintain a substantially uniform lateral force exerted by the turner regardless of pivotal movement of the turner caused, for example, by surface irregularities on the log, a pneumatic accumulator is installed in the line 102 supplying hydraulic fluid to end 103 of motor 66. Accumulator 100 includes a closed pressure vessel having a first chamber 104 in direct fluid communication with line 1112 through port 106, and a second smaller chamber 108 separated from chamber 104 by a rigid wall 110. A one way check valve 112 mounted in opening 114 of wall permits free flow of air from chamber 168 to chamber 164 but prevents flow of air or hydraulic-fluid in the reverse direction. Chamber 108 is connected through port 116 and conduit 118 to end 120 of motor 60, and a one way check valve 112 in line 118 permits free flow of air from end 120 of motor into chamber 108 upon movement of piston 71 in motor 60 in the direction to raise the turner to the log turning position. A one way check valve 124 permits ambient air to enter end 120 of motor 60 upon movement of piston 71 toward end 103 to lower the turner to the retracted position.

Fluid motor mounted on beam 26 for movement therewith, drives chain 44 through a chain and sprocket reduction mechanism 82. Pressure fluid is supplied to motor 80 through lines 84, 86 which may extend through hollow beam 26 for connection to flexible lines not shown extending through tubular member 34 and base 33.

To maintain proper tension on chain 44, sprocket 40 may be slidably mounted in adjustable mounting brackets in a manner well known in the art, and indicated generally at 88.

An angle member 90* having a horizontally extending leg 92 is mounted on the underside of carriage 10, and a similar angle member 94 having a horizontally extending leg 96 is fixedly secured to turner frame member 98. The angles 90, 94 are so positioned that, when the carriage is in the log unloading position, leg 92 on the carriage closely underlies leg 96, thereby positively preventing any vertical movement of the carriage as a result of vertical force by chain 44.

In the operation of a log turner according to the present invention, hydraulic fluid under pressure will be directed by a control valve 126 through line 102 to chamber 104 of accumulator and to end 103 of fluid motor 60 to raise the turner to a substantially vertical position until projections 46 engage a log 16 positioned on carriage 12. The hydraulic fluid under pressure entering chamber 104 will compress the air in this chamber at the same time it is moving piston 71 of motor \50 to pivot the turner about pivotal mounting 28. At the same time, movement of piston 71 toward end of motor 60 will force air from the fluid motor through one way check valve 122 and line 118 into chamber 108 of accumulator 100.

While the turner is maintained in contact with the log fluid pressure is applied to motor 80 to drive chain 44 in a direction to raise the outboard side and thereby turn the log on the carriage. The reaction force of the log acting through the chain will tend to rotate the turner in a direction away from the carriage and log due to the location of the pivotal mounting beneath the carriage at a point inboard from the point of contact of the chain with the log. However, by maintaining a uniform fluid pressure to motor 60 this tendency to rotate the turner in a direction away from the carriage will be resisted and a constant pressure will be applied to maintain the chain in contact with the log and to maintain the log in contact with adjusting knees 22. However, in the event surface irregularities or the like tend to increase the lateral load exerted on the turner, the air in chamber 104 of the accumulator will be further compressed, thereby permitting pivotal movement of the turner without substantially changing the lateral force, and at the same time provide quick recovery when the obstruction is removed so that the turner remains in contact with the surface of the log at a substantially constant uniform pressure.

When the log has been turned and properly positioned, the pressure to fluid motor 80 is stopped, thereby stopping chain 44. However, pressure is retained in motor 60 until the dogs (not shown) can be positioned to retain the log in position tightly against knees 22. At this point control valve 126 is actuated to permit hydraulic fluid to flow from end 103 of motor as and from chamber 104 of the accumulator, and the turner is returned by gravity to its retracted position beneath ramp 20 out of the way of the logs being moved onto the ramp. As

piston 71 moves toward end 103 of motor 60, air is drawn into end 120 through one way check valve 124, and, as pressure is reduced in chamber 104 of accumulator 100, the pressure in chamber 108 of the accumulator is permitted by check valve 112 to flow into chamber 104, thereby assuring a continuous supply of air in chamber 104.

If desired, rather than permit the turner to return to its fully retracted position, the flow of fluid from the motor and accumulator may be stopped when the turner is only partly retracted to permit more rapid positioning for successive turns of a log on the carriage, then fully retracted when it is desired to load another log on the carriage.

The hydraulic fluid reservoir (not shown) is vented to atmosphere to permit air to flow from the accumulator chamber 104, through line 102 upon complete retraction of the turner. This, by pumping air from end 120 of motor 60 into chamber 103 upon raising the turner, then permitting this air to flow through valve 112 into chamber 104 upon full retraction of the turner, an ample supply of air in chamber 104 will always be assured.

In turning a log which has had boards removed thereupon so as to present a smooth vertical sawn face to the turner, it is desirable that the teeth 46 "on the turning chain 44 not engage and mar or damage this smooth face. By providing the tapering wedge 48 beneath the bottom portion of chain 44, this bottom portion is projected outwardly from the face 50 of the turner so that, when the turner is in a vertical position, the bottom portion of the chain is inclined slightly away from the carriage and tends to engage the bottom portion of the log rather than the smooth vertical face.

While we have discussed and illustrated a preferred embodiment of our invention, we wish it understood that we do not intend to be restricted solely thereto, but that we do intend to cover all embodiments thereof which would be apparent to one skilled in the art and which come within the spirit and scope of our invention.

We claim:

1. In a saw mill having a log carriage movably mounted on a horizontal track and a loading ramp to facilitate loading logs on said carriage, a log loader comprising an elongated beam having a base portion extending beneath said carriage and pivotally mounting said beam for rotation between a substantially vertical log turning position at one side of the carriage and a substantially horizontal retracted position beneath said ramp, a pair of sprockets mounted on said beam, an endless chain carried by said sprockets and extending along the face of said beam adjacent said carriage when said beam is in said log turning position, means driving said sprockets in a direction to move said chain upwardly along said face, said chain having a plurality of teeth for engaging and turning a log positioned on said carriage, and actuating means including a motor for moving said turner from said retracted position to said log turning position and urging said chain into contact with a log on the carriage, said actuating means further including means for limiting the lateral force exerted by said turner on said log while permitting limited pivotal movement of said turner during the turning operation, said pivotal mounting of said base portion of said beam being positioned below said carriage at a point spaced laterally from said one side beneath said carriage a distance sufficient for the line of action of the reaction force exerted on said turner by a log being turned to pass outboard of said pivotal mounting whereby said reaction force will produce a turning moment in a direction urging said turner for rotation away from said carriage against the action of said actuating means.

2. The invention according to claim 1 wherein said means for limiting the lateral force exerted by said turner further includes means for maintaining a substantially constant lateral force exerted by said turner on a log being turned on the carriage while permitting limited pivotal movement of said turner during the turning operation.

3. The invention according to claim 1 wherein the means driving said sprocket and chain comprises a fluid motor mounted on and supported by said beam for pivotal movement therewith and drivingly connected to one of said sprockets.

4. In a saw mill having a log carriage movably mounted on a horizontal track and a loading ramp to facilitate loading logs on said carriage, a log loader comprising a beam pivotally mounted for rotation between a substantially vertical log turning position at one side of the carriage and a substantially horizontal retracted position beneath said ramp, a pair of sprockets mounted on said beam, an endless chain carried by said sprocket and extending along the face of said beam adjacent said carriage when said beam is in said log turning position, means driving said sprockets in a direction to move said chain upwardly along said face of said beam, said chain having a plurality of teeth for engaging and turning a log positioned on said carriage, said pivotal mounting of said beam being beneath said carriage at a point laterally spaced from said one side, fluid motor means moving said turner from said retracted position t-o said log turning position and urging said chain into contact with a log on the carriage, and pneumatic accumulator means operatively connected to said fluid motor to permit limited pivotal movement of said turner without substantially changing the the lateral force exerted by said turner on said log.

5. The invention according to claim 4 wherein said fluid motor means comprises an elongated cylinder having a piston reciprocally movable therein, a rod attached to said piston and extending through one end of said cylinder and operatively connected to said turner for pivotal movement thereof, means directing hydraulic fluid under pressure to said one end of said cylinder, and valve means at the end opposite said one end to permit ambient air to flow into said opposite end upon movement of said piston toward said one end, and to direct air from said opposite end to said accumulator when said piston moves from said one end to said other end.

6. A hydraulic actuating system comprising a fluid motor having a piston reciprocally mounted within an elongated closed cylinder, a rod attached to said piston for reciprocation therewith and extending through one end of said cylinder, fluid conduit means directing hydraulic fluid to the first end of said cylinder to drive said system toward the second end of said cylinder, a pneumatic accumulator having a trap chamber in direct fluid communication with the fluid in said conduit, and means responsive to actuation of said fluid motor for admitting ambient air Within said accumulator to automatically maintaining a supply of air in said trap chamber.

7. A fluid actuating system comprising an elongated closed cylinder, a piston reciprocally mounted within said cylinder, a rod attached to said piston for movement therewith and extending through one end of said cylinder, a first conduit directing hydraulic fluid to the first end of said cylinder to drive said piston toward the second end of said cylinder, a one way valve permitting air to be drawn into said second end ofsaid cylinder when said piston moves toward said first end, a pneumatic accumulator having a first trap chamber and a second trap chamber, said first trap chamber being in direct fluid communication with the fluid in said first conduit means, valve means between said first and second trap chambers to permit flow of air from said second to said first trap chamber and prevent flow of air or hydraulic fluid from said first to said second trap chambers, second fluid conduit means connecting said second trap chamber with said second end of said cylinder, and valve means in said second conduit means permitting flow of fluid from said second end of said cylinder to said second trap chamber and preventing flow in the opposite direction.

8. In a saw mill having a log carriage movably mounted on a horizontal track and a loading ramp to facilitate loading logs on said carriage, a log turner comprising a beam pivotally mounted for rotation between a substantially vertical log turning position at one side of the carriage and a substantially horizontal retracted position beneath said ramp, fluid motor means for moving said turner from said retracted position to said log turning position, an endless chain mounted on said beam and having a plurality of teeth for engaging and turning a log positioned on said carriage, means for driving said chain, and means for limiting the lateral force exerted by said turner on said log during the turning operation, said lateral force limiting means including accumulator means to permit limited pivotal movement of said turner without substantial change in the lateral force exerted by said turner.

References Cited by the Examiner UNITED STATES PATENTS 617,844 1/1899 Wilkin 143-99 902,142 10/1908 Foss et al. 143-102 2,367,009 1/1945 Davis 91-47 2,676,626 4/1954 Rumsey 143-102 2,955,576 10/1960 Hamilton 91-404 3,122,992 3/1964 Kautz -50 HAROLD D. WHITEHEAD, Primary Examiner.

WILLIAM W. DYER, JR., Examiner. 

1. IN A SAW MILL HAVING A LOG CARRIAGE MOVABLY MOUNTED ON A HORIZONTAL TRACK AND A LOADING RAMP TO FACILITATE LOADING LOGS ON SAID CARRIAGE, A LOG LOADER COMPRISING AN ELONGATED BEAM HAVING A BASE PORTION EXTENDING BENEATH SAID CARRIAGE AND PIVOTALLY MOUNTING SAID BEAM FOR ROTATION BETWEEN A SUBSTANTIALLY VERTICAL LOG TURNING POSITION AT ONE SIDE OF THE CARRIAGE AND A SUBSTANTIALLY HORIZONTAL RETRACTED POSITION BENEATH SAID RAMP, A PAIR OF SPROCKETS MOUNTED ON SAID BEAM, AN ENDLESS CHAIN CARRIED BY SAID SPROCKETS AND EXTENDING ALONG THE FACE OF SAID BEAM ADJACENT SAID CARRIAGE WHEN SAID BEAM IS IN SAID LOG TURNING POSITION, MEANS DRIVING SAID SPROCKETS IN A DIRECTION TO MOVE SAID CHAIN UPWARDLY ALONG SAID FACE, SAID CHAIN HAVING A PLURALITY OF TEETH FOR ENGAGING AND TURNING A LOG POSITIONED ON SAID CARRIAGE, AND ACTUATING MEANS INCLUDING A MOTOR FOR MOVING SAID TURNER FROM SAID RETRACTED POSITION TO SAID LOG TURNING POSITION AND URGING SAID CHAIN INTO CONTACT WITH A LOG ON THE CARRIAGE, SAID ACTUATING MEANS FURTHER INCLUDING MEANS FOR LIMITING THE LATERAL FORCE EXERTED BY SAID TURNER ON SAID LOG WHILE PERMITTING LIMITED PIVOTAL MOVEMENT OF SAID TURNER DURING THE TURNING OPERATION, SAID PIVOTAL MOUNTING OF SAID BASE PORTION OF SAID BEAM BEING POSITIONED BELOW SAID CARRIAGE AT A POINT SPACED LATERALLY FROM SAID ONE SIDE BENEATH SAID CARRIAGE A DISTANCE SUFFICIENT FOR THE LINE OF ACTION OF THE REACTION FORCE EXERTED ON SAID TURNER BY A LOG BEING TURNED TO PASS OUTBOARD OF SAID PIVOTAL MOUNTING WHEREBY SAID REACTION FORCE WILL PRODUCE A TURNING MOMENT IN A DIRECTION URGING SAID TURNER FOR ROTATION AWAY FROM SAID CARRIAGE AGAINST THE ACTION OF SAID ACTUATING MEANS. 